The low-temperature oxidation of the MoSi2 compound prepared by a self-propagating high temperature synthesis (SHS) reaction from a mixture of Mo and Si powders has been investigated by comparing the structural and chemical destructions of the MoSi2 compound. One of the comparable samples was a pellet sintered at 1700 oC and the other was synthesized powder annealed at 400 oC in air. The phase structure, microstructures, and chemical states of the samples were measured by XRD, SEM, and XPS. From the results of the analysis, the powder synthesized by SHS had a body-centred tetragonal MoSi2 crystal structure together with SiO2 and MoO3 amorphous phases from air contamination, the sample sintered at 1700 oC had a similar crystal structure to synthesized powder. On the other hand, the crystal structure of the powder annealed at 400 oC was destroyed completely into amorphous SiO2 and crystalline MoO3 phases and the loss of Mo content occurred by volatilizing MoO3.

Keywords: MoSi2, Self-propagating high temperature synthesis, Oxidation, XRD, XPS.